Central venous access (CVA) is one of the most commonly performed procedures in medicine. CVA is vital to many patients with acute and chronic illness. Hemodialysis and cardiac pacing are examples of life-sustaining therapies that would not be possible without central venous access.
CVA is typically obtained by using a large gauge needle to directly puncture first the skin and then one of the four large upper body veins, for example, the right or left internal jugular vein, or the right or left subclavian vein. After puncture, a guidewire is introduced through the needle and advanced into the central circulation. The channel is then dilated and a catheter or other medical device is advanced into the superior vena cava (SVC) or right atrium (RA).
Although central venous access is usually a straightforward procedure, there can be both short term and long term complications. Immediate risks include bleeding due to inadvertent puncture of carotid or subclavian arteries, and pneumothorax due to unintended puncture of a lung. These complications occur because central veins lie deep beneath the skin and are therefore not visible to the operator. As a result, there is often uncertainty about the location, depth and entry angle of the puncture needle, even when ultrasound guidance is used. The long-term risks of central access include venous occlusion, which can occur within days and is a common problem in patients requiring repeated access or semi-permanent access. Chronic venous occlusions occur when thrombus forms around a catheter or pacing lead, and then organizes into dense fibrous tissue that permanently obliterates the vessel lumen.
When confronted with occlusion of a central vein, physicians usually utilize one of the remaining veins in the upper body. The process can continue until all four central veins have been obliterated. However, once all four upper body central veins are lost the patient can have a life threatening access crisis.